scholarly journals An idealized physical model for the severe convective storm environmental sounding

2020 ◽  
Author(s):  
Daniel R. Chavas ◽  
Daniel T. Dawson
Keyword(s):  
Vertical Structure ◽  
Potential Utility ◽  
Convective Storm ◽  
Physical Processes ◽  
Simulation Experiments ◽  
Convective Storms ◽  
Independent Variation ◽  
Static Energy ◽  
Capping Inversion

AbstractThis work develops a theoretical model for steady thermodynamic and kinematic profiles for severe convective storm environments, building off of the two-layer static energy framework developed in Agard and Emanuel (2017). The model is phrased in terms of static energy, and it allows for independent variation of the boundary layer and free troposphere separated by a capping inversion. An algorithm is presented to apply the model to generate a sounding for numerical simulations of severe convective storms, and the model is compared and contrasted with that of Weisman and Klemp. The model is then fit to a case-study sounding associated with the 3 May 1999 tornado outbreak, and its potential utility is demonstrated via idealized numerical simulation experiments. A long-lived supercell is successfully simulated with the historical sounding but not the analogous theoretical sounding. Two types of example experiments are then performed that do simulate a long-lived supercell: 1) a semi-theoretical experiment in which a portion of the theoretical sounding is modified to match the real sounding (low-level moisture); 2) a fully-theoretical experiment in which a model physical parameter is modified (free-tropospheric relative humidity). Overall, the construction of this minimal model is flexible and amenable to additional modifications as needed. The model offers a novel framework that may be useful for testing how severe convective storms depend on the vertical structure of the hydrostatic environment, as well as for linking variability in these environments to the physical processes that produce them within the climate system.

Potential impacts of slum urbanisation on channel bank storage in the Bang Pakong River, Thailand

2012 ◽  
Vol 7 (4) ◽  
Author(s):  
K. Harriden
Keyword(s):  
Water Quality ◽  
Balance Equations ◽  
Physical Processes ◽  
Social Phenomena ◽  
Urban Settlements ◽  
Recharge Rates ◽  
Water Quality Deterioration ◽  
Informal Urban Settlements ◽  
Storage Processes

Generally regarded as social phenomena, this paper regards slum urbanisation as an environmental actor. Specifically, how slum developments modify hydrogeomorphological processes motivates this research. Using the Bang Pakong River, eastern Thailand, as a case study, a literature review was conducted. The literature reviewed indicated changes in physical processes such as channel bank stability, water quality, flow regimes and the hydrological balance equations can occur with slum development. Given the importance of channel banks as the physical basis of many slum sites, this paper focuses on the possible changes to channel bank storage in the Bang Pakong River following slum urbanisation. The research highlights possible changes to channel bank storage processes, notably decreased storage recharge rates; increased anthropogenic extraction; and probable water quality deterioration. Deeper scientific understanding of how river processes are affected by specific forms of urban development can contribute to better management of both informal urban settlements and rivers.

scholarly journals A regularized hidden Markov model for analyzing the ‘hot shoe’ in football

2021 ◽  
pp. 1471082X2110080
Author(s):  
Marius Ötting ◽  
Groll Andreas
Keyword(s):  
Markov Models ◽  
Hidden Markov ◽  
Simulation Experiments ◽  
Hot Hand ◽  
Special Cases ◽  
Psychology And Economics ◽  
Likelihood Approach ◽  
Penalized Likelihood Approach ◽  
Hot Hand Effect

We propose a penalized likelihood approach in hidden Markov models (HMMs) to perform automated variable selection. To account for a potential large number of covariates, which also may be substantially correlated, we consider the elastic net penalty containing LASSO and ridge as special cases. By quadratically approximating the non-differentiable penalty, we ensure that the likelihood can be maximized numerically. The feasibility of our approach is assessed in simulation experiments. As a case study, we examine the ‘hot hand’ effect, whose existence is highly debated in different fields, such as psychology and economics. In the present work, we investigate a potential ‘hot shoe’ effect for the performance of penalty takers in (association) football, where the (latent) states of the HMM serve for the underlying form of a player.

A Case Study of Gravity Waves–Convective Storms Interaction: 9 May 1979

1983 ◽  
Vol 40 (12) ◽  
pp. 2804-2830 ◽  
Author(s):  
James G. Stobie ◽  
Franco Einaudi ◽  
Louis W. Uccellini
Keyword(s):  
Gravity Waves ◽  
Convective Storms

scholarly journals A case study on availability of sensor data in agent cooperation

2010 ◽  
Vol 7 (3) ◽  
pp. 597-615
Author(s):  
Christian Johansson ◽  
Fredrik Wernstedt ◽  
Paul Davidsson
Keyword(s):  
Production Costs ◽  
Sensor Data ◽  
Energy Market ◽  
Physical Processes ◽  
Agent Based ◽  
Production And Distribution ◽  
Multi Agent ◽  
Problem Characteristic ◽  
Agent Cooperation

Multi-agent cooperation can in several cases be used in order to mitigate problems relating to task sharing within physical processes. In this paper we apply agent based solutions to a class of problems defined by their property of being predictable from a macroscopic perspective while being highly stochastic when viewed at a microscopic level. These characteristic properties can be found in several industrial processes and applications, e.g. within the energy market where the production and distribution of electricity follow this pattern. Another defining problem characteristic is that the supply is usually limited as well as consisting of several layers of differentiating production costs. We evaluate and compare the performance of the agent system in three different scenarios, and for each such scenario it is shown to what degree the optimization system is dependent on the level of availability of sensor data.

scholarly journals Vertical structure and physical processes of the Madden-Julian oscillation: Exploring key model physics in climate simulations

2015 ◽  
Vol 120 (10) ◽  
pp. 4718-4748 ◽  
Author(s):  
Xianan Jiang ◽  
Duane E. Waliser ◽  
Prince K. Xavier ◽  
Jon Petch ◽  
Nicholas P. Klingaman ◽  
...  
Keyword(s):  
Vertical Structure ◽  
Madden Julian Oscillation ◽  
Physical Processes ◽  
Climate Simulations

Spontaneous Aggregation of Convective Storms

2021 ◽  
Vol 54 (1) ◽  
Author(s):  
Caroline Muller ◽  
Da Yang ◽  
George Craig ◽  
Timothy Cronin ◽  
Benjamin Fildier ◽  
...  
Keyword(s):  
Hydrological Cycle ◽  
Theoretical Work ◽  
Annual Review ◽  
Publication Date ◽  
Tropical Atmosphere ◽  
Physical Processes ◽  
Convective Storms ◽  
Warming Climate ◽  
Cloudy Region ◽  
Self Aggregation

Idealized simulations of the tropical atmosphere have predicted that clouds can spontaneously clump together in space, despite perfectly homogeneous settings. This phenomenon has been called self-aggregation, and it results in a state where a moist cloudy region with intense deep convective storms is surrounded by extremely dry subsiding air devoid of deep clouds. We review here the main findings from theoretical work and idealized models of this phenomenon, highlighting the physical processes believed to play a key role in convective self-aggregation. We also review the growing literature on the importance and implications of this phenomenon for the tropical atmosphere, notably, for the hydrological cycle and for precipitation extremes, in our current and in a warming climate. Expected final online publication date for the Annual Review of Fluid Mechanics, Volume 54 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Effects of rotational submarine slump dynamics on tsunami genesis: new insight from idealized models and the 1929 Grand Banks event

2020 ◽  
Vol 500 (1) ◽  
pp. 41-61 ◽  
Author(s):  
T. Zengaffinen ◽  
F. Løvholt ◽  
G. K. Pedersen ◽  
C. B. Harbitz
Keyword(s):  
Source Information ◽  
Physical Processes ◽  
Viscoplastic Model ◽  
Grand Banks ◽  
Rotational Kinematics ◽  
Short Run ◽  
Submarine Slump ◽  
Geological Source ◽  
Insight Into

AbstractSediment slumps are known to have generated important tsunamis such as the 1998 Papua New Guinea (PNG) and the 1929 Grand Banks events. Tsunami modellers commonly use solid blocks with short run-out distances to simulate these slumps. While such methods have the obvious advantage of being simple to use, they offer little or no insight into physical processes that drive the events. The importance of rotational slump motion to tsunamigenic potential is demonstrated in this study by employing a viscoplastic landslide model with Herschel–Bulkley rheology. A large number of simulations for different material properties and landslide configurations are carried out to link the slump's deformation, rheology, its translational and rotational kinematics, to its tsunami genesis. The yield strength of the slump is shown to be the primary material property that determines the tsunami genesis. This viscoplastic model is further employed to simulate the 1929 Grand Banks tsunami using updated geological source information. The results of this case study suggest that the viscoplastic model can be used to simulate complex slump-induced tsunami. The simulations of the 1929 Grand Banks event also indicate that a pure slump mechanism is more tsunamigenic than a corresponding translational landslide mechanism.

Remarks about factors shaping the heliosphere

2018 ◽  
Vol 92 (3) ◽  
pp. 329-335
Author(s):  
Romana Ratkiewicz ◽  
Wojciech Konior ◽  
Jan Kotlarz
Keyword(s):  
Status Report ◽  
Physical Processes ◽  
Content Type ◽  
General Review ◽  
New Information ◽  
Conceptual Paper ◽  
First Time ◽  
Practical Implications ◽  
Theoretical Results

Purpose The purpose of the paper is to give a brief description of the new topic introduced for the first time at the EASN Conferences. Design/methodology/approach The topic concerns the heliosphere, the nearest surrounding of the Sun and thus the nearest vicinity of the Earth. The heliosphere is created due to the interaction between the solar wind and the local interstellar medium. Findings This paper does not include any new information about the heliosphere and only introduces a new topic to this journal. It is briefly shown how heliospheric structures are formed, what factors affect a shape of the heliosphere, what measurements are made by Ulysses, Voyager and IBEX space missions (important for the heliosphere modeling) and how obtained data are used to validate theoretical results. Practical implications To categorize the paper under one of these classifications, research paper, viewpoint, technical paper, conceptual paper, case study, literature review or general review, the authors chose a paper type, general review, as the closest category to this paper. However, it is not a purpose of this paper to provide an extensive review of the community efforts to investigate the physical processes in the vicinity of the heliosphere interface. This is mostly a status report. Originality/value As the new topic in this journal, the article introduces in detail only a small number of aspects connected with heliosphere models. Interplanetary and interstellar magnetic field structures are primarily described. Other factors are only mentioned.

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